Compare 21/40 and 42/70
21/40 is smaller than 42/70
Steps for comparing fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 70 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 40 × 7 = 280,
21/40 = 21 × 7/40 × 7 = 147/280 - Likewise, for the 2nd fraction, since 70 × 4 = 280,
42/70 = 42 × 4/70 × 4 = 168/280 - Since the denominators are now the same, the fraction with the bigger numerator is the greater fraction
- 147/280 < 168/280 or 21/40 < 42/70
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